The present invention relates to a method for producing laminated cloth-like products of wrap and weft webs having each a large width and having optional combinations of fiber density in warp and wefts. Further it relates to an improvement in the method of the prior invention made by the present inventors (U.S. Pat. No. 3,859,156).
In the above-mentioned prior invention, cut weft webs are adhered successively one by one onto the upper surface of a circulating lattice conveyer and then advanced to the lower side surface thereof where they are pushed downward one by one by reciprocating action of a number of linear edges thrusted out from and drawn back into between the lattice members of said conveyer so as to fly the cut weft web toward a warp web running crosswise below.
However, in the practice of said method, it has been found that this method has the following drawbacks:
A drawback lies in that the weft webs loaded on the upper surface of the circulating conveyer must be turned around the turning point and conveyed to the position to be pushed down as stated above, and hence, if the web is stiff, thick or of a high density, as in case of the web of glass fiber yarns or robings, or a thick organic fiber web, the web is apt to drop spontaneously off the conveyer, while going too far beyond the turning point due to difficulty in turning around said turning point, unless the turning curvature thereof is sufficiently large.
Another drawback lies in that if a weft web is heavy in weight per unit area, or the web is composed of a comparatively small number of yarns and insufficient in the contact area for adhering to the surface of the conveyer, the web is apt to drop spontaneously off said surface on the lower side circulation route thereof even when the web may turn around said turning point. Accordingly in these cases, the surface area of the conveyer to which the web is adhered, should be increased as much as possible.
Once thus said surface is increased, however, a further trouble may occur in that if the web having a large contact area is to be cross-laminated, the web is difficult to be peeled off from said increased surface when pushed downwards. This fact teaches that the surface area of the conveyer should be changed as the contact area of the web to be cross-laminated changes.
A further drawback lies in that as linear edges for pushing the cut weft web downwards are drawn back halfway, they do not hit the surface of the warp web in the abovementioned mentioned prior invention. Accordingly, the web is apt to be subjected to occasional disorderly overlaying, due to disturbance of the surrounding air while flying downwards and moreover subjected to fluctuation in overlaid position on the warp web, especially when the cross-lamination speed is changed, say at the time of starting.
The above-mentioned drawbacks are several examples of those as seen in the cross-lamination operation. However, even in the case of the method of the above-mentioned prior invention, if the tops of said linear edges are so thrusted out as to hit in a moment the surface of the warp web, at least, the drawback mentioned just above is avoided, and uniformly cross-laminated product may be obtained.
Thereafter an improved method over the prior invention has been found and filed on Jan. 21, 1976 as U.S. Ser. No. 651,106 (parent application of the present C.I.P. application), entitled "method for producing a product comprising weft webs of a large width continued in the warp direction," wherein cut webs for wefts were successively connected in the warp direction by selvedges adhered onto both the margins of the cut weft webs. The product can be made into a cross-laminated product by merely laminating with a warp web in case of necessity.
Said method comprises circulating two right and left heated belts having thereon a hot melt type adhesive in a tacky state and spaced by the length of each of cut webs for wefts; adhering onto each of the belt, selvedge material to constitute the selvedges of final product; suddenly dropping the two belts having the selvedges adhered thereto, respectively, on the lower circulating route of the belts, down onto one of cut weft webs loaded successively and at a given gap on a conveyer circulating below the belts and perpendicularily thereto, over the length corresponding to the width of the webs for wefts, when both the ends of one of the cut weft webs and corresponding belts overlapped each other, thereby to adhere both the ends of the cut weft web onto the corresponding belts having selvedge materials thereon and said adhesive on the lower surfaces, and just thereafter suddenly elevating the belts thereby to strip and hang up the cut weft web adhered onto the belts from the conveyer; repeating the above-mentioned procedure; and peeling the resulting belts having successive cut weft webs adhered thereon without leaving any gaps therebetween and selvedge materials also adhered thereto from the belts.
The method further comprises circulating a plurality of belts provided between said belts above-mentioned, and providing a plurality of yarns on said plurality of circulating belts in advance.
In the course of further researches, it has become clear that, in place of said hot melt type adhesive, a liquid having adhesion property can be used for picking up cut weft webs while adhering onto the belts, and at the same time, said selvedge materials are not always necessary, since transferring of the continued cut weft webs adhering to the circulating belts has been found to be possible even without providing selvedge materials onto a warp web, which is most simply a set of two selvedge materials of the improved invention, and further, belts or a plurality of belts for picking up cut weft webs, in some cases, can be replaced by the warp web itself. Thus the method of the present invention is provided.
Although the method described above, wherein weft webs are moved onto the warp web to be overlaid without flying in the air between the two is an improved method over the prior invention, the method of the present invention wherein a warp material comprising a warp web, a belt means circulating in the warp direction and a combination of said belt means with a warp web moves towards the weft webs to touch and pick up them one by one, is quite different from the prior invention. Thus the present invention can be said as a kind of improved method of the previous one.